Honing device



May 1945.

J. SUNNEN HONING DEVIC Filed Aug, 1 3

VENT0 JOSEPH SUNNEN BY Patented May 22, 1945 UNITED STATES PATENT OFFICE nonz i s vica Joseph Snnne'n, Clayton, Mo. Application August 16, 1943, Serial No. 498,841

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This invention relates to honing devices and particularly to hones for finishing the interior surfaces of very small bores. Up to the present time, it has not been considered practical or economical to hone the surfaces of small bores, because previous hone designs could not be reduced to the dimensions necessary for operation in very small holes without such sacrifice of strength and rigidity as to .make the unusable. The term "small used herein is intended to refer to holes in the order of /2" or less in diameter, although it will be understood that certain featin'es of my invention may be used in connection with hones for larger holes.

In order to successfully finish holes by the honing process, it is necessary to provide a hone capable of being held against the surface of the metal with considerable force, as, otherwise, the hone is inclined to slide over the surface of the metal without cutting at aratewhich would be practical commercially. Also, the hone must have as great a surface as possible in contact with the surface of the hole as the rate of stock removal may be said to vary directly with the product of the contact area and the unit pressure on such area.

The hone is usually mounted on a rotating shaft, and the work is held manually or otherwise in such a manner as to float on the hone, hone shaft, and arbor. In order to obtain a rapid and smooth cut, it is necessary that the work be given a reciprocating longitudinal movement with respect to the shaft, because such movement not only keeps the individual projections of the granular surface of the hone from forming grooves, but also clears the minute chips of metal from the cutting surfaces of the granule at each reciprocation, The length of the hole being fixed and perhaps limited, it is necessary or at least highly desirable to have the hone of considerably greater length than the length of the hole which is to be finished. If the diameter of the hole is small, the hone and arbor assembly must be long and slim and therefore comparatively flexible. The abrasive stick which forms the honing su face proper is relatively inflexible and therefore it must be supported with great rigidity.

The hone, hone support, and hone arbor must extend into the hole together with the wedge or adjusting means which is used to force the hone outwardly against the surface of the hole. The hone arbor is provided with a longitudinal groove to receivethe hone, hone support, and wedge, and this groove leaves a mere shell which must nevertheless have such great strength and rigidity as to drive the hone without bending or twisting even when considerable forcev is applied to the honeby the wedge. As will be understood by those skilled in the art. any twisting or rocking in the groove may result in chattering or variation in the diameter along the axis of the hole.

It is an object of my'invention to provide a hone, hone arbor, and wedge of such construction as to manually support each other in operation, so that the assembly can stand the greatest possible twisting, rocking, and other strains without flexing sufficiently to cause hone breakage or less of straightness of the holes.

It is a further object of my invention to provide a hone of comparatively great length with respect to its cross section and so constructed and arranged as to be held with an even pressure against the hole at all points of contact.

It is a further object of m invention to provide a hone, hone arbor, and wedge assembly constructed and arranged in such a manner as to prevent a maximum resistance to the rocking of the hone in the groove during the honing operat on.

Other objects and advantages of my invention will be apparent from the following specification and accompanying drawing, referring to which:

Figure 1 is a longitudinal sectional .view'of a hone arbor assembly embodying my invention.

Figure 2 is a longitudinal plan view of the cam or wedge member shown in Figure 1.

Figure 31s an elevation of the opposite side of the wedge member shown in Figures 1 and 2.

Figure 4 is an enlarged end view of the structure shown in Figure 1.

Figure 5 is an enlarged side view of the hone member shown in Figures 1 and 4.

Figure 6 is an end view of the hone member shown in Figure 5.

Figure '1 shows a slightly modified form of hone.

Figure 81s a bottom view of the hone shown in Figure 7.

Figure 9 shows another modified form of hone.

Figure 10 is a top view of-the body member of the hone shown in Figure 9, the abrasive stick being removed for clearness of illustration.

Figure 11 is a bottom view of the body member shown in Figure 10.

Figure 12 shows a side elevation of the front end of the arbor assembly shown in Figure 1.

Figure 13 shows the form of wedge which is used in connection with the hone shown in Figures 7 and 8.

The reference numeral i indicates a chuck or drive shaft constructed and arranged to flt into a standard honing machine, such as shown in my Patent No. 2,070,381.. For present purposes,

' it is suflicient to say that this machine provides for the rotation of the member I at a suitable speed and also has provision for operating the hook 2 to the right or left with respect toFigure l. The hone arbor 3 fits into an axial bore in the member I and is held in position by any suitable means, such as a set screw 4. "The hone arbor is provided with a longitudinal groovej 5' extending its full length, and the bottom of this I groove is cut square at one corner as indicated at I in Figure 4 and beveled at the other corner as indicated at 8 for reasons which will be hereinafter pointed out.

A wedge member 9 is slidably' mounted in one side of the groove with its lower edge resting against the bottom pfthe groove. This wedge member carries the hook 2-at one end thereof and is held in position by portions l and ll in slidable contact with themember I. The wedge member 9 is preferably formed of a thin strip of sheet metal. with parallel upper and lower edges, asshown and parallel cam surfaces l2 and" which are formedj by cutting away approximately one-half the thickness of the outer end of the wedge and by cutting of! the remaining metal at the end of thewedge, respectively. Ahone support It is snugly fitted to the groove at the side of the wedge so as to take up all the lateral space not occupied by the wedge. However, the fit is such as to permit sliding movement of the wedge longitudinally of the hone arbor and radial movement of the hone support.

The hone support is provided with an abrasive stick l which is secured to its upper edge. The hone support is provided with a recess It at one side of its rear end in such a manner as to provide a cam surface I! for cooperating with the cam I2 of the wedge so that the longitudinal movement of the wedge will produce radial movement 'of the hone with respect to the hone arbor. Particular attention is called to the fact that the cams l2 and I! are located at. one side of the center line; that is to say, the hone is supported at its rear end at a point on one side of the plane P-P, Figure 4, passed through the axis of the hone arbor parallel to the walls of the groove while the center of the operating surface of the abrasive stick isv on the opposite side of the same plane. I g e The hone support is provided near its forward end with an extension l8 having a cam surface 19 at itslower side to cooperate with the cam 13 on the end of the wedge 9. Attention is also called to the fact that this projection supports the hone at a point further spaced from the plane P-P than the cam II, so that a plane passed through any point S in the operating surface of the hone, as indicated at 20, and the centers of the support surfaces l l and I!) will form an angle to the axis of the hone arbor. By this arrangement, the twisting and rocking action of the hone in the groove is more effectively resisted than if the force polygon was in a plane parallel to the axis of the arbor. This arrangement also makes it impossible to set up the harmonic vibration in thehone known as chattering.

The member I8 is further extended beyond the cam surface l3, as indicated at 2|, to COOP eff ate with the slot. 22 which is formed in the front end of the hone arbor. This slot is at the end of the hone opposite the driving means.

In the particular form of mechanism shown, no provision is made for automatically retracting the hone when the wedge is withdrawn, as the operator can press the hone back into place whenever it is necessary to start operation on a new piece. However, I have providedfor retaining the hone in position by'means of a" springpressed member 23 which extends along the slot beside the wedge member il and] contacts the inner end of the hone, as indicated at 24. The

rear end of the member23 is bent into a U-shape and provided with a head 25 which is slidable in the bore 26 in the member I. A spring 21 is provided to yieldably move the retainer 23 toward the right, the thrust being taken by contact of the member l8 with the free wall of the slot 22, thus effectively preventing accidental 'dislodgement of the hone from the slot.

It will be noted that the greater part of the hone is to the right of the plane PP- which 7 passes through the axisof the hone as shown in Figured. Therotation of the bone ispref erably in the direction indicated by the arrow or anti-clockwise with respect to Figure 4, so that the surface of the'hone maybe said tofollow the center plane ofthe groove.

While it is impossible to provide an absolutely rigid assembly and support for the hone, I have found that it ispossible to obtain satisfactory results and maximu'm'straightness of the finished holes by locating the cam surfaces l1 and I9 eccentricallywith respect to the center'of the bone. Preferably, the cam surface 19 at the forward end of the hone is spaced at a'slightly greater distance fromthe' front end than thecam 'I'I is spaced from the rear 'end, as this arrangement not only helps in maintaining straightness of the finis hd hole but also provides more space for operation of the cam in finishing blind holes. r

In Figures '7 and 8, Ihave shown a construction in which the cam surfaces 28 and 29 are alined, whichis a satisfactory arrangement in some cases where the travel of the wedge isnot limited as it would be'in finishing blind holes.

The extension 30 in Figures '7 and 8 extends into the slot 22 of the arborto prevent longitudinal movement, but its lower surface, is not used as a cam as in Figure 5..

The wedge member 32 shown in Figure'13 issimilar to the wedge 9 ,shownin Figures 2 and 3, except that the single, cam'surface 33 extends substantially the fulllength of the hone and engages both of the earns '28 and 29. e

The hone shown in Figures 9, 10 and 11 is useful in constructions in which it'is' desirable to have as great a, hone surface as possible, as there is a partial supporting surface for a hone which may be the full width of the" hone support at the point 3| in Figure 10, and the hone may overhang the hone support as indicated in Figure 11.

vices comprising an elongated support member having an abrasive stick attached to the upper side thereof and a pair of longitudinally spaced parallel cam surfaces, one of said surfaces being formed beneath the body member and the other being formed on a projection from the side of said support member.

3. In a small bore honing device, a hone comprising an elongated support member having substantially parallel sides and edges, an abrasive element secured to one of said edges, a cam portion formed in said support member at a point directly opposed to said abrasive element, and a second cam portion formed on said support member, said second cam being both longitudinally and laterally spaced from the first cam.

4. A small bore hone comprising an elongated body member having an abrasive element secured substantially co-extensively with one edge thereof, cam portions formed near opposite ends of said body member, one of said cam portions being formed in a recess of said 'body' member directly opposite a portion of said abrasive element, and the other being formed on a projection from the side of said body member, whereby the plane of the force triangle formed by application of force at said cam surfaces and resistance at the surface of said abrasive element is at an angle to the axis of said element.

5. A hone comprising an elongated substantially rectangular support member having an abrasive element secured to one side thereof, lon gitudinally spaced parallel cam surfaces formed in said body member opposite said abrasive element at points adjacent the ends thereof, said cam surfaces being arranged on opposite sides of a plane which is parallel to the longitudinal axis of said Support member and perpendicular to the planes of said cam surfaces, and a projection formed at one side of said hone and overlying one of said cam surfaces for holding it against longitudinal movement. 1

6. A hone comprising an elongated substantially rectangular support member having an abrasive element secured to the upper side thereof, a cam surface formed in said body member opposite said abrasive element, a projection extending from one side of said body member, the lower side of said projection having a cam surface parallel to and at one side of said first named cam, and said projection being extended to provide means for limiting the longitudinal movement of the hone.

I. A small bore honing device comprising an arbor having driving means at its rear end, a longitudinal groove in said arbor, a hone in said groove comprising a substantially rectangular body member having upper and lower edges and substantially parallel sides, a recess at the rear end of said member, said recess having a wall forming a cam surface, a projection near the other end of said member, said projection having a lower side forming a cam surface, and a radially extending slot in the side of said groove near the front end of the arbor for receiving said projection.

8. A hone comprising a substantially rectangular and elongated body member having substantially parallel sides, a recess formed in the lower side of said body member near the rear end thereof, said recess having an upper side forming a cam surface, aprojection extending from said body member near the front end thereof, said ing irregularly spaced with respect to the ends of said body member.

9. In combination, a hone arbor having a longitudinal groove therein, a, wedge member longitudinally slidable in said groove, said wedge member having a pair of longitudinally spaced cam surfaces lying in parallel planes, said cam surfaces being located on opposite sides of a plane parallel to the axis of said hone arbor and perpendicular to said parallel planes, and a hone comprising a body member snugly fitting said groove at the side of said wedge member and having cam surfaces cooperating with the cam surfaces of said wedge member.

10. A wedge for honing devices comprising a body member having operating means formed at one end thereof and an extension at the other end thereof, said extension having parallel upper and lower edges and being comparatively thin with respect to its width, said extension having a cam surface formed at an angle to its axis by cutting away a portion of its thickness, and

a second cam surface formed parallel to said first being in contact with a wall of said groove, said wedge member having a cam surface formed at a point spaced from the end thereof by cutting away substantially one half of its thickness, a second cam surface formed on the upper edge of said wedge member substantially at the end thereof, a hone support mounted in said groove, said hone support having one side in substantially co-extensive contact with said wedge member, and its other side in substantially coextensive contact with the opposite side of said roove.

12. In combination, a hone arbor having a longitudinal groove therein, an elongated wedge member of comparatively small thickness with respect to its width, the lower edge of said wedge member lying in sliding contact with the bottom of said groove, one face .of said wedge member being in contact with a wall of said groove, and wedge member having a cam surface formed at a point spaced from the end thereof by cutting away substantially one half of its thickness, a second cam surface formed on the upper edge of said wedge member substantially at the end thereof, a hone support mounted in said groove. said hone support having one side in substantially co-extensive contact with said wedge member and its other side in substantially co-exiensive contact with the opposite side of said groove, said arbor being constructed and arranged to rotate in su a direction that the hone precedes the wall of the groove with which it is in contact. whereby the hone will be prevented from twisting in the groove by contact of its upper side with the upper wall of said groove and by contact of its opposite lower edge with said wedge.

JOSEPH BUNKER. 

